Tooth loss from periodontal disease or dental caries afflicts most adults over the course of their lives. Goals of professional dental treatment and of personal oral health self-care are to prevent tooth loss and maintain the natural dentition in a state of comfort and function. In order to develop appropriate dental treatment planning, dental health care professionals must weigh the long-term outlook for retention of each tooth against the cost and discomfort involved with each treatment option, and patients and third-party payers must make value judgments about the cost of suggested dental treatments against the probability of long-term success for those treatments. Hence, it is essential to utilize dental prognosis in the development of any dental treatment plan. Goals: The primary goal of this study is to apply newly developed multivariate extensions of Classification And Regression Trees (CART) for survival to a large, de-identified database obtained from the AxiUm system of electronic dental records at Creighton University School of Dentistry to establish global dental prognostic indicators based on actual tooth loss. We also plan to refine computer algorithms we developed for multivariate CART for survival to increase computing efficiency and further extend Bayesian survival trees and random forests to correlated outcomes in order to utilize the most accurate procedure for establishing criteria for assignment of dental prognosis Subjects: The hypotheses will be tested on a 4-year longitudinal database consisting of 19,092 men, women, and children with follow-up data who have been treated at the Creighton University dental clinic. Of the 19,092 patients with follow-up data, 4,339 adults are regular patients in the periodontal clinic with follow-up periodontal records while 1,681 are children under 18 years of age. Available data for testing hypotheses: Data for age, gender, race in some records, time until tooth loss, complete restorative and periodontal records with follow-up, significant medical history, smoking, oral hygiene, special needs, compliance, frequency of dental visits and other parameters that are collected as part of dental treatment and follow-up at the Creighton University School of Dentistry. Significance: By establishing clear, objective criteria for assignment of accurate, evidence-based global dental prognostic indicators that are based on actual tooth loss, this study has the potential to make a tremendous impact on the dental community. Adoption and use of accurate, evidence-based global dental prognostic indicators could aid dental practitioners in better treatment planning, help third-party payment plans make better decisions about benefits, and provide patients with an avenue for making informed decisions about their dental treatment needs. PUBLIC HEALTH RELEVANCE: The objective of this proposal is to identify simple, objective clinical criteria for assignment of global dental prognostic indicators that are based on actual tooth loss. The central hypothesis is that commonly used clinical measures can be used to forecast the long-term prognosis of any tooth in a patient's mouth at any given time. Development, adoption, and use of accurate, evidence-based global dental prognostic indicators has the potential for making a significant public health impact by aiding dental practitioners in better treatment planning, helping third-party payment plans make better decisions about benefits, and providing patients objective criteria for making informed decisions about their dental treatment needs.